Data center architectures are evolving to meet the demands and complexities imposed by increasing business requirements to stay competitive and agile. Industry trends such as data center consolidation, server virtualization, advancements in processor technologies, increasing storage demands, rise in data rates, and the desire to implement “green” initiatives can cause stress on current data center designs. Consolidation of input/output in the data center, allowing Fibre Channel and Ethernet networks to share a single, integrated infrastructure, helps enterprises address some of these challenges. An important pillar of this consolidated approach is Fibre Channel over Ethernet (FCoE).
The Ethernet network that supports FCoE is required to be a lossless Ethernet network, with switching devices that have internal architectures designed to offer a no-drop packet capability and network flow control mechanisms to enable lossless transmission of packets across the Ethernet infrastructure. Ethernet supports flow control to enable lossless operation, but flow control can require large amounts of buffering. Lossless operation over Ethernet cannot be supported over distances where bandwidth delay product requirements exceed buffer resources. Thus, managing resources to provide a lossless operation over long-distance links can present significant challenges to network operators.